Working machine for operating as an auxiliary power plant

A method for increasing reliability and capacity of power supply needed by devices connected to an electrical power network, the method comprising:

• connecting a working machine to the electrical power network and using the working machine as an auxiliary power plant, the working machine comprising:
• a combustion engine,
• an electromechanical power transmission chain between the combustion engine and one or more actuators of the working machine,
• an electrical connector system configured to attach at least one electrical cable mechanically to the working machine and configured to electrically connect to an external electrical power network through the electrical cable, and
• an electronic power converter configured to transfer electrical energy from the electromechanical power transmission chain through the electrical cable to the external electrical power network and from the external electrical power network through the electrical cable to the electromechanical power transmission chain, the electronic power converter enabling the working machine to be energized by the external electrical power network when a capacity of the external electrical power network is sufficient, and alternatively to be used as an auxiliary power plant for increasing a capacity of power supply needed by external devices connected to the external electrical power network.